document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=89006>Question 89006</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You scored 88.7, 91.2, and 94.6 on your last three test scores. Find the standard deviation of your test scores. <BR>\n" );
document.write( "A. 0.95  <BR>\n" );
document.write( "B.1.22  <BR>\n" );
document.write( "C.2.42  <BR>\n" );
document.write( "D.4.35\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #64694 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=64694\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First lets find the mean:\r<BR>\n" );
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document.write( "To find the mean, add up all of the numbers and divide the sum by the number of numbers (which in this case is 3).\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Mean=%2888.7%2B+91.2%2B+94.6+%29%2F3=274.5%2F3=91.5 ALIGN=MIDDLE  ALT=\"Mean=%2888.7%2B+91.2%2B+94.6+%29%2F3=274.5%2F3=91.5\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the mean is 91.5\r<BR>\n" );
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document.write( "Use this formula to find the standard deviation:\r<BR>\n" );
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document.write( "Standard Deviation:<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE  \sigma=\sqrt{ \frac{1}{N}\displaystyle\sum_{i=0}^N (x_i-\bar{x})^2}\"> where <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \bar{x}\"> is the mean, <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE x_i\"> is the ith number, and <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE N\"> is the number of numbers\r<BR>\n" );
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document.write( "So we can replace N with 3\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE\sqrt{ \frac{1}{3}\displaystyle\sum_{i=0}^3 (x_i-\bar{x})^2}\">\r<BR>\n" );
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document.write( "Replace  <IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \bar{x}\"> with 91.5\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE\sqrt{ \frac{1}{3}\displaystyle\sum_{i=0}^3 (x_i-91.5)^2}\">\r<BR>\n" );
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document.write( "Expand the summation (replace each <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5Bi%5D ALIGN=MIDDLE  ALT=\"x%5Bi%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > with the respective number)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%281%2F3%29%28%2888.7-91.5%29%5E2%2B%28+91.2-91.5%29%5E2%2B%28+94.6+-91.5%29%5E2%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Subtract the terms in the parenthesis\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%281%2F3%29%28%28-2.8%29%5E2%2B%28-0.3%29%5E2%2B%283.1%29%5E2%29%29 ALIGN=MIDDLE  ALT=\"sqrt%28%281%2F3%29%28%28-2.8%29%5E2%2B%28-0.3%29%5E2%2B%283.1%29%5E2%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Square each term\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%281%2F3%29%287.84%2B0.09%2B9.61%29%29 ALIGN=MIDDLE  ALT=\"sqrt%28%281%2F3%29%287.84%2B0.09%2B9.61%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Add up all of the terms\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%281%2F3%2917.54%29 ALIGN=MIDDLE  ALT=\"sqrt%28%281%2F3%2917.54%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Multiply\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%285.84666666666667%29 ALIGN=MIDDLE  ALT=\"sqrt%285.84666666666667%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >  \r<BR>\n" );
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document.write( "Take the square root\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2.41798814444295 ALIGN=MIDDLE  ALT=\"2.41798814444295\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the standard deviation is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2.41798814444295 ALIGN=MIDDLE  ALT=\"2.41798814444295\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So if you round to the nearest hundredth, you get 2.42. So the answer is C) </SPAN>\n" );
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